Molecular Genetics

Unit 1 Exam

Genetics

The study of heredity and inherited variation.

Heredity

The transmission of genetic information from one generation to the next.

Gene

A unit of heredity; a segment of DNA encoding a functional product.

Allele

A variant form of a gene at a particular locus.

Genotype

The genetic makeup of an organism, specifically the alleles present at one or more loci.

Phenotype

The observable characteristics of an organism resulting from the interaction of its genotype with the environment.

DNA

The molecule that carries genetic information.

Nucleotide

The basic building block of DNA and RNA, consisting of a sugar, phosphate, and nitrogenous base.

mRNA

RNA that carries the genetic code for a protein.

tRNA

RNA that carries amino acids to the ribosome for protein synthesis.

Transcription

The process of copying DNA into RNA.

Translation

The process of synthesizing a protein from mRNA.

Lac Operon

A cluster of genes transcribed together under the control of a single promoter, involved in lactose metabolism.

Operon

A cluster of genes transcribed together under the control of a single promoter.

Pleiotropy

A situation where a single gene affects multiple phenotypic traits.

Polygenic Inheritance

A situation where a single characteristic is affected by mutations in multiple genes.

Mutation

A change in the DNA sequence.

Frameshift Mutation

An insertion or deletion of nucleotides that alters the reading frame of a gene.

Cis-acting Element

A DNA sequence that affects the expression of genes on the same chromosome.

Trans-acting Factor

A protein that binds to DNA and affects gene expression.

F-factor

A fertility factor or episome in bacteria capable of being either a free plasmid or integrated into the host bacterial chromosome.

Epigenetics

The study of heritable changes in gene expression that do not involve alterations to the DNA sequence itself.

Genome

The total genetic material of an organism.

Homozygous

Having two identical alleles at a particular locus.

Heterozygous

Having two different alleles at a particular locus.

Haploid

Containing one set of chromosomes (1n).

Diploid

Containing two sets of chromosomes (2n).

Phenotype

The observable characteristics of an organism.

DNA Replication

The process of duplicating DNA.

Rho-dependent termination

In prokaryotes, termination of transcription by an interaction between RNA polymerase and the rho protein.

Rho-independent termination

Sequence-dependent termination of prokaryotic mRNA synthesis; caused by hairpin formation in the mRNA.

Transposable Element

A DNA sequence that can move from one location to another in the genome.

Wild-type

The normal, non-mutated form of a gene or phenotype.

Cis vs. Trans-acting Elements

Cis-acting elements are DNA sequences that regulate neighboring genes, while trans-acting factors are usually proteins that can regulate genes located on different DNA molecules.

Nutritional influence on Transgenerational Inheritance

Nutritional factors can influence epigenetic modifications that can be passed down through generations.